TD 传输信道物理信道映射.ppt

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1、ServicesprovidedbythephysicallayerForTD-SCDMA(R4)CreatedbyFanjianfaInterfacestothephysicallayerThephysicallayer(layer1)isthelowestlayerintheOSIReferenceModelanditsupportsallfunctionsrequiredforthetransmissionofbitstreamsonthephysicalmedium.ThephysicallayerinterfacestheMed

2、iumAccessControl(MAC)LayerandtheRadioResourceControl(RRC)Layerasdepictedinfigure:MACThephysicallayerinterfacestheMACentityoflayer2.CommunicationbetweenthePhysicalLayerandMACisinanabstractwayperformedbymeansofPHY‑primitivesdefinedwhichdonotconstrainimplementations.ThePHY‑p

3、rimitivesexchangedbetweenthephysicallayerandthedatalinklayerprovidethefollowingfunctions:-transferoftransportblocksovertheradiointerface;-indicatethestatusofthelayer1tolayer 2.FormatsandconfigurationsforL1datatransferLayer2isresponsibleforthemappingofdataontoL1viatheL1/L2

4、interfacethatisformedbythetransportchannels.Inordertodescribehowthemappingisperformedandhowitiscontrolled,somedefinitionsandtermsarerequired.Therequireddefinitionsaregiveninthefollowingsubclauses.Notethatthedefinitionsaregenericforalltransportchanneltypes,i.e.notonlyforDC

5、Hs.AllTransportChannelsaredefinedasunidirectional(i.e.uplink,downlink,orrelay-link).ThismeansthataUEcanhavesimultaneously(dependingontheservicesandthestateoftheUE)oneorseveraltransportchannelsinthedownlink,andoneormoreTransportChannelintheuplink.TransportBlockTransportBlo

6、ck:ThisisthebasicunitexchangedbetweenL1andMAC,forL1processing.Layer1addsaCRCforeachTransportBlock.TransportBlockSet:ThisisdefinedasasetofTransportBlocks,whichareexchangedbetweenL1andMACatthesametimeinstanceusingthesametransportchannel.TransportBlockSize:Thisisdefinedasthe

7、numberofbitsinaTransportBlock.TheTransportBlockSizeisalwaysfixedwithinagivenTransportBlockSet,i.e.allTransportBlockswithinaTransportBlockSetareequallysized.TransportBlockSetSize:ThisisdefinedasthenumberofbitsinaTransportBlockSet.TransmissionTimeInterval:Thisisdefinedasthe

8、inter-arrivaltimeofTransportBlockSets,andisequaltotheperiodicityatwhichaTransportBlockSetistrans